Designers used to take great pains to avoid sole-sourced components. Years ago, I think that was very wise. Maybe it still is, but there are so many specialized chips out these days that I'm not sure how practical or at all realistic it is.
If they lost the supplier for the FCRAM, they'd have to re-design some other type of RAM in.; maybe even take a performance hit. However, if their CPU went unavailable, they'd most likely have to make some design changes to get another manufacturer's CPU in there.
Rather than looking at sole sourced components, I'd be interested to see how many key components are not sole-sourced.

The mere fact that the FCRAM is being used is exciting. And, despite the potential downside of having a single supplier, sometimes that is the only way to get a jump out ahead of the competition. Of course, if FCRAM finds it's way into a number of products or even only a couple of big selling products, then it should be only a short time until there is a second source available.